The preparation of metal salts of various carboxylic acids such as methacrylic acid is described in several patents. U.S. Pat. No. 4,082,288, for instance, relates to the preparation of basic zinc methacrylate by milling under agitation methacrylic acid with a suspension of zinc oxide in a liquid medium such as water or a volatile organic liquid.
U.S. Pat. No. 4,100,182 relates to a method for preparing an adjuvant for an elastomeric composition which involves mixing methacrylic acid with zinc oxide in a liquid medium in the proportions required to form basic zinc methacrylate, removing the liquid medium and finely dividing the resulting reaction product. The reference teaches that the liquid medium may be water or a volatile organic liquid such as a hydrocarbon liquid or an alkanol.
In U.S. Pat. No. 4,500,466, owned by the Assignee of record herein, a method is provided for the preparation of zinc methacrylate powder involving the reaction of zinc oxide and methacrylic acid in a liquid aliphatic hydrocarbon such as hexane.
Despite the existence of metal salts of carboxylic acids and their widespread use in rubber polymer compounds the present invention provides a novel form of such salts and method for the preparation thereof. These salts provide superior physical properties in vulcanizable rubbers compounded therewith.